Abstract: An Electro-Magnetic Imaging (EMAI) System is presented. EMAI systems can include induction elements (e.g., an induction coil) configured to induce a target tissue to generate internally sourced ultrasounds. The induction elements can be shielded by one or more shielding elements to shape, or otherwise alter, an imaging field while attenuating radiated fields in a far zone. EMAI systems can further include a shield tuner to adjust shield parameters to achieved desired imaging or radiated field properties. A shielding element can be placed approximately one induction coil radius away from the coil to achieve suitably strong imaging field magnitudes while also achieving suitably weak radiated field magnitudes in a far zone. In some embodiments, acoustic sensors lack substantial shielding from the fields generated by the induction elements.

Abstract: Methods and systems for using ground penetrating radar (GPR) to obtain subsurface images. The depression angle, frequency, and polarization can all be adjusted for the soil conditions at hand. In particular, the depression angle is set at the “pseudo-Brewster angle” for improved ground penetration.

Abstract: Methods for remotely detecting a gun muzzle flash, using frequency-optimized detection methods. Small explosive charges are best detected at I/R and visible wavelengths, using optical detectors, whereas large explosive charges may also be detected with antennas. Details of the time course and spectral properties of the flash can be used to distinguish gun muzzle flashes from other radiation.

Abstract: Methods for remotely detecting a gun muzzle flash, using frequency-optimized detection methods. Small explosive charges are best detected at I/R and visible wavelengths, using optical detectors, whereas large explosive charges may also be detected with antennas. Details of the time course and spectral properties of the flash can be used to distinguish gun muzzle flashes from other radiation.

Abstract: A sensitive photon detection system generates an electronic photon sensor signal as a K factor times a number N photons per unit time. The system is configured by combining a separate optical amplifier with a gain factor K1 with a photo detector with a gain factor K2 such that K may be realized as the product of K1 and K2. The values of K1 and K2 are chosen to meet a predetermined K while optimizing a signal quality of the photon sensor signal. The optical amplifier may be preceded by a photon gathering device and/or a light chopping device to further optimize system performance. Further, the photon sensor signal may be further processed analog circuitry or may be digitized and processed using digital signal processing to generate an enhanced photon sensor signal with enhanced signal quality by adding gain and/or bandwidth limiting.

Abstract: Methods and systems are described for efficiently detecting an object. The system includes at least one electrode for measuring a displacement current. The at least one electrode is coupled to a floating ground configuration provided by an op-amp, where the inverting node of the op-amp is coupled to electrode and the non-inverting node is coupled to a signal generator. The system may include a single capacitance sensor for detecting an object. Systems may include a plurality of capacitance sensors in an array configuration for detecting an object.

Abstract: A method of detecting and treating cancerous or cancer-supporting tissue by applying low-power density electromagnetic signals to the tissue, inducing acoustic signals from a portion of the tissue that exhibits an electrical conductivity gradient, receiving the thus-induced acoustic signals and from them identifying the location of the tissue portion, applying time-reversal to the thus received acoustic signals, accumulating the strength of the time-reversed acoustic signals, and then applying the thus strengthened acoustic signals to the identified tissue portion.

Abstract: Methods and systems for using ground penetrating radar (GPR) to obtain subsurface images. The depression angle, frequency, and polarization can all be adjusted for the soil conditions at hand. In particular, the depression angle is set at the “pseudo-Brewster angle” for improved ground penetration.

Abstract: A sensitive photon detection system generates an electronic photon sensor signal as a K factor times a number N photons per unit time. The system is configured by combining a separate optical amplifier with a gain factor K1 with a photo detector with a gain factor K2 such that K may be realized as the product of K1 and K2. The values of K1 and K2 are chosen to meet a predetermined K while optimizing a signal quality of the photon sensor signal. The optical amplifier may be preceded by a photon gathering device and/or a light chopping device to further optimize system performance. Further, the photon sensor signal may be further processed analog circuitry or may be digitized and processed using digital signal processing to generate an enhanced photon sensor signal with enhanced signal quality by adding gain and/or bandwidth limiting.

Abstract: Methods and systems are described for efficiently detecting an object. The system includes at least one electrode for measuring a displacement current. The at least one electrode is coupled to a floating ground configuration provided by an op-amp, where the inverting node of the op-amp is coupled to electrode and the non-inverting node is coupled to a signal generator. The system may include a single capacitance sensor for detecting an object. Systems may include a plurality of capacitance sensors in an array configuration for detecting an object.

Abstract: An acoustic data collection system that uses an antenna array aboard a powered unmanned and remotely controlled parafoil. The antenna array has multiple microphone elements, whose outputs are combined to provide directionality to the data acquisition.

Abstract: A system that remotely measures displacement between two objects. A passive sensor is affixed to each object, such that the sensors are substantially parallel. Each sensor has a permeable rod, a surrounding coil, and a tuning capacitor, and have substantially the same resonant frequency. When an interrogating device is placed near the sensors, the frequency responses of the sensors indicates their relative displacement and thus the displacement between the objects.

Abstract: A system that remotely measures displacement between two objects. A passive sensor is affixed between the objects. The internal sensor uses magnetic coupling between two sensor elements to measure their relative displacement. The sensors are either a) a permeable rod and a complimentary coil in parallel with a tuning capacitor; or b) two permeable rods, each having its own surrounding coil and a tuning capacitor. One of the sensor elements is affixed to each object which is to be monitored. When an interrogating device is placed near the sensors, a resonance can be measured whose frequency characteristics change in a reproducible manner with the relative displacement of the sensors. The resulting resonance characteristics can be calibrated in such a way as to enable the displacement of the objects to be determined.

Abstract: A method of two interferometric configurations to measure bending of an extended element. The measurement arm of each configuration is a long optical fiber. A first interferometric configuration has a segment of its measurement arm attached to one side of the element. The second interferometric configuration has a segment of its measurement arm attached to one side of the element and another segment of its measurement arm attached to an opposing side of the element. The two configurations are used to obtain two sets of interference fringe measurement values. If one set is subtracted from the other, the result is intensity differential values that indicate only the effects of bending and not of temperature or pressure. Variations of the method can be used for irregularly shaped elements.

Abstract: A system that remotely measures displacement between two objects. A passive sensor is affixed between the objects. The internal sensor uses magnetic coupling between two sensor elements to measure their relative displacement. The sensors are either a) a permeable rod and a complimentary coil in parallel with a tuning capacitor; or b) two permeable rods, each having its own surrounding coil and a tuning capacitor. One of the sensor elements is affixed to each object which is to be monitored. When an interrogating device is placed near the sensors, a resonance can be measured whose frequency characteristics change in a reproducible manner with the relative displacement of the sensors. The resulting resonance characteristics can be calibrated in such a way as to enable the displacement of the objects to be determined.

Abstract: A waveguide designed to minimize bend-induced losses. The waveguide has three regions of varying indices of refraction. The indices of refraction are chosen so that the field is a trigonometric function in the core region, evanescent in the intermediate region, and trigonometric again in the outer region. The widths of each region are calculated to further reduce losses.

Abstract: A pressure or temperature sensor array utilizing a combination of liquid crystal material and charge coupled device (CCD) sensor array. The device generally comprises a liquid crystal material enclosed in a planar capsule, one side of which has a flexible outer membrane which is placed on the surface whose pressure and/or temperature is to be measured; a light source used to illuminate the liquid crystal material; and a charge coupled device (CCD) array which detects the variations in the optical signature of the liquid crystal material due to changes in pressure or temperature. The device may further include an optical waveguide for controlling transmission of light from the light source to the liquid crystal material.